Ground terminal



Feb. 13, 1934. KOCH, JR 1,946,862

GROUND TERMINAL Filed Dec. 10, 1931 Ennentor 719' ZOMZ'JA. ffochJr Gttorneg Patented Feb. 13, 1934.

1,946,862 GROUND murmur.

Louis A. Koch, Jr., Louisville, Ky.

Application December 10, 1931 Serial No. 580,147

2 Claims.

My invention relates to ground terminals and refers more particularly to a new and improved electrical connecting element adapted for the attachment of cables or other electrical conductors 5 to a metallic ground. My present novel device is especially useful in the battery systems of automobiles wherein one of the electrodes of the battery is connected directly to the chassis of the vehicle and it is at this latter point of connection that considerable trouble is experienced in making and maintaining a suitable contact of sufficient capacity. The frame or chassis of an automobile is of steel and hence a poor conductor of electricity and in addition the element of corrosion which is ever present in battery connections makes it very difilcult to utilize the ordinary terminals of other electrical devices. My present ground terminal overcomes all of the aforesaid objectionable features and provides a connecting element which is capable of satisfactory and continued use over a long period of time.

One of the principal objects of this invention is to provide a ground connection having a conducting member or surface of suflicient magnitude and carrying capacity to insure the durability thereof over an extended period of usage. Among other objects of my invention is the simplicity in construction and cheapness of manu- 3o facture of the present terminal.

terminal connection which is particularly adaptable for the attachment of ribbon type cable. My terminal is so constructed that the end of the ribbon cable is positively and firmly gripped by integrally formed elements which prevent the spreading of the cable and in some cases eliminating the necessity of soldering.

To the accomplishment of the foregoing and related ends, said invention, then, consists of the means hereinafter fully described and particular ly pointed out in the claims. The annexed drawing and the following description set forth in detail certain mechanism embodying the invention, such disclosed means constituting, however, but

one of the various mechanical forms in which the principal of the invention may be used.

In said annexed drawing- Figure 1 is an elevational view showing my novel ground terminal in use, the battery and automobile chassis being only fragmentarily shown;

Figure 2 is a perspective view of the ground terminal connection seen in Figure 1; and

Figure 3, a perspective view of said terminal before attachment to the cable conductor.

In the embodiment of this invention illustrated A still further object hereof is to provide a in the aforesaid drawing I have shown at 10 a portion of an ordinary battery provided with a binding post or electrode 11. The automobile chassis is illustrated at 12 in section and constitutes the usual channel shaped longitudinally extending member, to one portion of which a connection from the battery post 11 is madeto establish an electrical ground from said battery to the automobile frame.

As stated hereinbefore this frame of the automobile is constructed of steel and accordingly 9. poor conductor and it is one of the objects of my invention to so construct the ground terminal element that it may have an increased carrying capacity over ordinary terminals thus insuring a better electrical connection.

In Figure 3 there is shown my improved ground terminal before it is attached or connected to the cable conductor. This ground terminal preferably consists of a casting providing a rectangularly shaped base 13 having a flat bottom 14 and providing in its upper surface a rectilinearly shaped recess 15. This recess is bounded on its side edges by raised ribs 16 which serve, as will be hereinafter described, in conjunction with the 30 grip element to prevent side-wise spreading of the cable conductor. The front end of the recess 15 is open as at 17, and at the rear end 18 of the recess is formed integrally with the base 13 a grip element 19, this latter being constructed sub- 35 stantially complemental to the form of the recess 15. As manufactured my ground terminal connection is cast with the grip element 19 at an angular position relatively to the base 13 as seen best in Figure 3.

As also stated above this invention is best adapted for use with ribbon type cable and in Figures 1 and 21 have shown a cable 20 of this type secured to my ground terminal. The end 21 of the cable in assembly is placed within the recess 15 and thereafter the grip element 19 is swaged or bent parallel to the base 13, which operation serves to firmly grip the cable between the underside 52 of the grip element 19 and the top of recess 15. As seen in Fig. 2 the side edges 23 of the grip element 19 substantially fill the space between the ribs 16 and hence any tendency to spread the cable 20 beyond the confines 01' the recess 15 is overcome. It has been found that by constructing the present ground terminal of cast metal, the same having of course suflicient malleability to be slightly worked without breaking, the end of the cable 20 will be so tightly held in the recess 15 by the grip element 19 that the necessity of soldering the cable in place may in some cases be done away with. It is tobe understood, however, that my invention is not limited to making the present ground terminal of a casting, and thatthesamemaybemadeofsheetmetaland satisfactorib used due to certain other incidental advantageous features of construction which will be presently set forth. Ihave also illustrated in Fig. 3 at 24 a plurality of raised projections on the surface of the base 13 within the recess 15. These projections as will be obvious serve to bite into the cable and more firmly hold the same from displacement. Both the base 13 and the grip element 19 are provided with allned holes and 26, respectively, which are adapted to receive the bolt 27 when attaching the ground terminal to the automobile frame 12. By arranging the bolt holes through the base and grip element of my ground terminal connection, I derive an additional force to maintain the end 21 of the cable within the recess 15. It will be quite apparent from an inspection of the drawing that the tighter the bolt 27 is applied the more firmly the grip element 19 will be drawn toward the base 13. When solder is omitted from this terminal the aforesaid action of the bolt will adequately serve to hold the cable 20 in its place in the terminal connection. These bolt holes may be formed at a stage in the manufacture of the terminal before the attachment of the cable or may be drilled after the grip member is in locked relation to the base and cable end 21. I have also formed integrally with my present ground terminal connection means on its upper surface to prevent the turning of the nut 28 at g the upper end of bolt 27. This means preferably consists of a raised projection 29 provided adjacent the hole 26 on the upper surface of the grip element 19 and having a substantially straight face 30 adapted to cooperate with one of the faces of the nut 28 as clearly shown in Figure 1. Although I have shown in the drawing the nut 28 as being held from rotation by the projection 29 on my improved terminal, it is of course intended that this projection may also serve to prevent rotation of the bolt itself should the same be used in the inverse position to that shown.

It will be apparent from an understanding of the foregoing that I have devised an improved ground terminal in compliance with the objects set forth and that I have provided a new and improved ground terminal connection which serves as a better contacting element in making the connection from a battery to the steel frame of a motor vehicle. As previously stated in the speciilcation steel is not as good a conductor as the material usedin the terminals or cable elements and hence it is desirable to provide a ground terminal connection which has an enlarged contacting surface. In ordinary constructions this increased contact is sometime established by the use of more than one bolt. In contradistinction the present invention provides the base 13 of the ground terminal considerably larger than the portion forming a connection with the cable 20 and a single bolt is used to attach the same to the frame 12 as shown in Figure 1. By employing this enlarged contact base 13 the device balances the conductivity of the electric current where two dissimilar metals of different conductivity are used, and further, the present device, by increasing this contacting area eliminates the necessity of enlarging the conductor or wire itself.

I claim:

1. A ground terminal for simultaneous connection against the flat surface of a member and with one end of a ribbon cable, said terminal comprising a plate having its bottom face flat for continuous contact with the surface, a tongue integral with the plate and-rising from the top surface thereof at an inclination, spaced ribs on the top face of the plate, said tongue being bendable at its junction with the plate into clamping relation upon one end of a ribbon terminal disposed therebeneath and between said ribs on the top face of the plate, said tongue and plate having openings therein which register when the tongue is clamped upon a cable whereby a fastening element may be passed through the tongue and base for securing the terminal to a member and intensifying the clamping action of the tongue upon the cable.

2. In a ground connection, a member constituting a ground and having a flat surface, a plate having its bottom face flat and in continuous contact with the flat surface of the member, a ribbon cable, a tongue integral with the plate and bent to clamp one end of the cable between it and the plate, a bolt extending through the member, plate, cable and tongue, a nut threaded on the bolt, and 2. lug on the tongue coacting with one member of the bolt and nut to lock the latter against rotation.

LOUIS A. KOCH, JR. 

